Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van phan » van phong, van thanh, luan phan
duoc van » duc van, duoc ban, duoc dan
hanh tai » thanh tai, hang tai, han tai
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
duoc va » nuoc va, duc va, duoc ma
nang o » nang co, nang ho, nang ro
cuc te » cua te, cuc thue, cuc tieu
o hoc » co hoc, mo hoc, so hoc

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty nang o hoc. hieu van phan ((duoc van) OR (duoc va)) hanh tai cuc te~".
• Adding a wildcard symbol may retrieve word variants: so sach ty nang o hoc. hieu van phan ((duoc van) OR (duoc va)) hanh tai cuc te*.